Create price alert

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=false, openWorldHint=true, idempotentHint=false and destructiveHint=false, so the safety profile is covered. The description adds non-obvious behavior the annotations cannot convey: app notification delivery and the market-dependent direction inference, including the US limitation.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two tightly packed sentences with zero filler; the core action is front-loaded and the caveat is attached to the parameter it affects rather than tacked on at the end.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 5-parameter mutation with no output schema and rich annotations, the description covers the operation, the tricky inference rule and the market exception. It does not mention what is returned on success, which is the only notable gap.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the baseline is 3, but the description genuinely extends `direction` semantics beyond the field text ('derived from the current price if omitted') by explaining the US case where inference is impossible. Other parameters (market, price, symbol, frequency) are left to the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description gives a specific verb+resource plus the triggering behavior: 'Creates a price alert that notifies the user in the Thndr app when the instrument crosses `price`.' This clearly separates it from get_alerts/get_alert/update_alert/delete_alert by operation type, though it never names those siblings explicitly.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It supplies a concrete conditional rule for a non-obvious parameter: direction is inferred from current price unless given, and must be supplied explicitly in the US because no whole-market snapshot exists there. That is real when-to-do-what guidance, though it does not discuss alternatives or prerequisites like auth.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.